Role of Nano-SiO₂ Dispersion in Tetrahydrofuran Hydrate Induction Time through Image Analyses

Clathrate hydrate has extensive applications in many engineering fields due to its specific characteristics. The commercial application is limited by its slow formation rate. As an accelerator of hydrate nucleation, nanoparticles in the solution can provide more nucleation sites for the hydrate nucleation process and shorten the induction time for its engineering applications. In this study, we used the constant subcooling method to investigate the effect of nano-SiO₂ particles with the mass concentrations of 0.2, 0.5, 1, 2, and 5 mg/mL on the dispersion of tetrahydrofuran hydrate induction time. The results showed that the number of crystallization points with different additive amounts of nano-SiO₂ particles can be divided into four stages during the hydrate formation process, reflecting the changes of molecular clusters and crystallization. The standard deviation variation of dispersion of induction time showed an initial increase followed by a decrease and finally stability under the combined effects of van der Waals force and double layer electrostatic forces of nano-SiO₂ particles. We analyzed the effect of mass concentration of particles on the mechanism of these two forces and got an optimal mass concentration of 0.5 mg/mL that was conductive to the hydrate nucleation process.